JP2004322638A - Printer, print head, and printing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printer, a print head, and a printing method, which can print with a clear ink at a desirable timing. <P>SOLUTION: A print head has a first nozzle row having a plurality of nozzles for ejecting an ink not containing any coloring material disposed in the conveying direction, and a second nozzle row having a plurality of nozzles for ejecting inks containing coloring materials disposed in the conveying direction. The first nozzle row is disposed at least on the upstream side or the downstream side of the second nozzle row in the conveying direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a printing device, a printing head, and a printing method.

  2. Description of the Related Art An ink jet printer is one type of output device for outputting images processed by a computer or images captured by a digital camera. An ink jet printer prints an image by discharging ink to form dots on a print medium.

    Ink jet printers use inks in which dyes or pigments or the like are dissolved in a solvent. In recent years, inks that do not include coloring materials such as dyes or pigments and have specific functions (hereinafter, referred to as “clear inks”) have been used. It has been used to improve printing characteristics. Specifically, the clear ink is used for the following purposes.

(1) Improvement of gloss unevenness (2) Improvement of ink bleeding etc. (3) Improvement of printing speed

  First, (1) “improvement of gloss unevenness” will be described.

    In general, pigment-based inks have a high gloss (the ratio of light incident at a fixed angle reflected at the same diagonal), so if there are high and low dot densities, there will be a difference in the gloss. This causes uneven gloss and gives an unnatural feeling. FIG. 9A is a diagram schematically illustrating a cross section of a dot formed by the dye-based ink. FIG. 9B is a diagram schematically illustrating a cross section of a dot formed by the pigment-based ink.

  As shown in FIG. 9A, the dye-based ink 301 penetrates well into a print medium (for example, print paper) 300. On the other hand, as shown in FIG. 9B, since the pigment-based inks 302 and 303 hardly penetrate into the print medium 300, the pigments in the extremely dark colors (that is, the parts where the pigment ink adheres very much) The island of the ink 303 is formed on the surface of the print medium 300 and thickly covers the surface, completely hiding the texture of the surface of the print medium 300.

  The surfaces 300a and 302a of the very light-colored portions where the texture of the surface of the print medium 300 is well exposed generally have low light reflectance, whereas the surface 303a of the island of the pigment ink 303 which is the very dark-colored portion Has a relatively high light reflectance due to the characteristics of the ink. Therefore, when the surfaces 300a and 302a having a low light reflectance and the surface 303a having a high light reflectance are adjacent to each other, the surface 303a of the portion having a high light reflectance may be noticeably seen as "teratera".

    In addition, since the surface 303b of the edge portion of the island of the pigment ink 303 (that is, the portion where the brightness is rapidly changed) is inclined, depending on the viewing angle or the angle of incidence of light, only the portion has a feeling that it is “terateki”. May look prominent. Such a difference in light reflectance on the surface of the printed matter, that is, a difference in glossiness is presumed to be a cause of unevenness in gloss of the printed matter using the pigment ink.

(1-A) Therefore, an ink (clear ink) having the same glossiness as that of the pigment-based ink and containing no color material is formed by an ink containing a color material (hereinafter, referred to as “color ink”). The unevenness of gloss is reduced by hitting a dot having a low density of dots.

  (1-B) In addition, the above-described clear ink is not applied only to a portion having a low dot density, but is applied to the entire image, so that the image is uniformly overcoated, thereby improving the gloss unevenness. It has also been done.

  Next, (2) “Improvement of ink bleeding” will be described.

  (2-A) In recent years, in order to improve image quality, the size of dots is reduced by reducing the size of ejected ink to reduce the granularity, and expression can be performed without increasing the matrix size of one pixel. The number of gray levels has been increased. However, when the ink bleeds on the print medium, the formed dots cannot be made sufficiently small despite the size reduction, and the image quality deteriorates due to the bleeding of the ink. In some cases.

    Various media are used as printing media. Therefore, depending on the type, there are cases where the ink does not have sufficient color developing properties, fixing properties, and drying properties to obtain satisfactory image quality.

    Therefore, in order to prevent such a problem, a chemical change is caused between the ink and the color ink, thereby causing ink bleeding, ink coloring, fixing properties, and drying properties (hereinafter referred to as “bleeding etc.”). ) Is prevented by bleeding the clear ink, which is produced by dissolving a substance which improves the above-mentioned method), into a portion where dots are formed by color ink or in the vicinity thereof.

(2-B) In recent years, there has been a printing medium provided with a coloring layer on the surface in order to realize high-quality printing by reducing the granularity of dots. Printing media provided with a color-forming layer can be broadly classified into two types, a so-called absorption type and a swelling type. The absorption type medium refers to a medium that develops a color when a coloring material contained in the ink is adsorbed on a pigment such as silica or alumina contained in the coloring layer. The swelling type medium refers to a medium in which a polymer such as gelatin is contained in the color-forming layer, and the polymer swells by absorbing the ink and forms a color by confining the ink inside. While silica and other materials used in absorption-type media are often chemically bonded to the colorant, polymers such as gelatin are often difficult to chemically react with the colorant. No change occurs, and the light resistance is excellent.

  By the way, the print medium provided with the coloring layer improves image quality for a natural image in which dots are formed relatively densely, but resembles bleeding in an image having a low dot recording rate such as a ruled line. A phenomenon may occur. This is because, for example, in the case of a swelling-type medium, when a new ink droplet is ejected before one dot is completely dried, the dot and the ink droplet are in a state where the medium can swell. Mix to form one large dot. On the other hand, when the drying and fixing of the dot are completely completed, the portion cannot absorb more ink droplets, and the ink droplets subsequently ejected are around the dot, and the ink is discharged. A dot is formed at a position where it can be absorbed. Therefore, in the case of a ruled line or the like, it is visually recognized as rattling. A similar phenomenon occurs not only when ink is ejected over a dot but also when ink is ejected close to the dot.

    Therefore, in order to avoid such a problem, a clear ink consisting only of a solvent is injected into a portion where the dot is formed or in the vicinity thereof, thereby preventing the dot from drying and preventing blurs such as ruled lines from occurring. Reductions have been made.

  Finally, (3) “improvement of printing speed” will be described.

    As described above, when the ejection ink is reduced into small droplets for high image quality, the image quality is improved, but for example, when performing the so-called “solid printing” that requires printing the same color on one surface, Since it is necessary to print a small amount of droplets over the entire surface of the print medium, it is necessary to repeat the printing operation, and as a result, there is a problem that the printing speed is reduced.

Therefore, by discharging clear ink (ink containing only a solvent without containing a coloring material) so as to be adjacent to the dot formed by the color ink, the diffusion of the ink is induced and the size of the formed dot becomes larger than usual. The printing speed is also improved by enlarging the printing speed (see Patent Document 1).
JP 2001-205827 A (Detailed Description of the Invention)

By the way, with respect to the above-described improvement of (2-A) such as ink bleeding, it is desirable to print the clear ink before printing the color ink.
Regarding the above-described (1-A) and (1-B) improvement of gloss unevenness, (2-B) improvement of ink bleeding such as ruled lines, and (3) improvement of printing speed, clear ink It is desirable to print after printing the color ink.

    However, in the related art, there is a problem that the clear ink cannot be printed at a suitable timing because the timing of printing the clear ink has not been sufficiently considered.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a printing apparatus, a print head, and a printing method that can print clear ink at a suitable timing. Things.

The main present invention is the following printing apparatus.
(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head having a plurality of nozzles for ejecting ink to form dots on a medium transported by the transport mechanism,
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
A printing device having
The printing apparatus, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the transport direction.

Further, another main aspect of the present invention is the following printing apparatus.
(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head that has a plurality of nozzles for ejecting ink to form dots on a medium conveyed by the conveyance mechanism, and moves in a predetermined direction to perform printing.
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
Has,
The printing apparatus, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the predetermined direction.

Further, another main aspect of the present invention is the following printing apparatus.
(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head which has a plurality of nozzles for ejecting ink to form dots on a medium conveyed by the conveyance mechanism, and performs printing by moving in a predetermined direction and a reverse direction. ,
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
Has,
In the predetermined direction, the first nozzle row is disposed upstream and downstream of the second nozzle row, respectively.
A printing apparatus which performs printing using one of the first nozzle rows arranged on the upstream side and the downstream side and the second nozzle row during printing.

Another main aspect of the present invention is the following print head.
A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
The print head, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the transport direction.

Another main aspect of the present invention is the following print head.
A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
In the transport direction, the first nozzle row is disposed on at least one of an upstream side and a downstream side of the second nozzle row,
A print head in which the ink having no color material is ejected from the first nozzle row before the ink is ejected from the second nozzle row.

Another main aspect of the present invention is the following print head.
A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
In the transport direction, the first nozzle row is disposed on at least one of an upstream side and a downstream side of the second nozzle row,
A print head in which the ink having no color material is ejected from the first nozzle row after the ink is ejected from the second nozzle row.

Another main invention is a printing method as described below.
A printing method,
Transporting the medium in the transport direction;
Discharging ink having no color material onto the medium;
Ejecting the ink having no coloring material onto the medium, and then ejecting the ink having the coloring material;
A printing method.

Another main invention is a printing method as described below.
A printing method,
Transporting the medium in the transport direction;
Discharging ink having a color material onto a medium;
Ejecting the ink having the coloring material onto the medium, and then ejecting the ink having no coloring material;
Printing method having

  Other features of the present invention will be apparent from the accompanying drawings and the following description.

  At least the following matters will be made clear by the description in this specification and the accompanying drawings.

(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head having a plurality of nozzles for ejecting ink to form dots on a medium transported by the transport mechanism,
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
A printing device having
The printing apparatus, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the transport direction.
Therefore, it is possible to print ink having no coloring material at a suitable timing.

  Further, the first nozzle row may be arranged upstream of the second nozzle row in the transport direction.

  Further, the second nozzle row may include a plurality of nozzle rows for ejecting inks of different colors. This makes it possible to print ink of a different color after the ejection of the ink having no color material is completed.

    Further, the ink having no color material may be an ink that is desirably ejected before the ink having the color material. As a result, it is possible to print the ink having no coloring material in an optimal order.

    Further, the ink having no coloring material may be an ink which causes a chemical reaction with the ink having the coloring material, and the ink having no coloring material may prevent bleeding and improve color development. The ink may be an ink for the purpose of improving, fixing, or drying. This makes it possible to reliably eliminate bleeding and to improve the coloring, fixing and drying properties.

    Further, the first nozzle row may be arranged downstream of the second nozzle row in the transport direction.

  Even in such a case, the second nozzle row may include a plurality of nozzle rows for ejecting inks of different colors. This makes it possible to eject ink without a color material after the ejection of inks of different colors is completed.

  Further, the ink having no coloring material may be an ink that is desirably printed after the ink having the coloring material. As a result, it is possible to print the ink having no coloring material in an optimal order.

  Further, the ink having no coloring material may be an ink for the purpose of preventing bleeding, improving coloring properties, improving fixing properties, or improving drying properties. This makes it possible to reliably eliminate bleeding and gloss unevenness and improve the printing speed.

  Further, in the transport direction, the first nozzle row is disposed on the upstream side and the downstream side of the second nozzle row, and the ink having no color material is supplied from these first nozzle rows. It may be ejected appropriately.

(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head that has a plurality of nozzles for ejecting ink to form dots on a medium conveyed by the conveyance mechanism, and moves in a predetermined direction to perform printing.
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
Has,
The printing apparatus, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the predetermined direction.
Therefore, it is possible to print ink having no coloring material at a suitable timing.

  Further, in the predetermined direction, the first nozzle row may be arranged downstream of the second nozzle row, and in the predetermined direction, the first nozzle row may be arranged in the second nozzle row. May be arranged on the upstream side of the nozzle row, and in the predetermined direction, the first nozzle row is arranged on the upstream side and the downstream side of the second nozzle row. The ink having no coloring material may be appropriately ejected from one nozzle row. This makes it possible for the printer to print the ink having no color material in an optimal order without complicating the control.

(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head which has a plurality of nozzles for ejecting ink to form dots on a medium conveyed by the conveyance mechanism, and performs printing by moving in a predetermined direction and a reverse direction. ,
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
Has,
In the predetermined direction, the first nozzle row is disposed upstream and downstream of the second nozzle row, respectively.
A printing apparatus which performs printing using one of the first nozzle rows arranged on the upstream side and the downstream side and the second nozzle row during printing.
Therefore, it is possible to print ink having no coloring material at a suitable timing.

  Further, at the time of printing, among the first nozzle rows arranged on the upstream side and the downstream side, the first nozzle row located on the leading side in the moving direction of the print head; Printing may be performed using the two nozzle arrays. This makes it possible for the printer to print the ink having no color material in an optimal order and to improve the printing speed.

    Further, during printing, of the first nozzle rows arranged on the upstream side and the downstream side, the first nozzle row located on the rear side in the direction in which the print head moves, and Printing may be performed using the two nozzle arrays. This makes it possible for the printer to print the ink containing no coloring material in an optimal order and to improve the printing speed.

A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
The print head, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the transport direction.
Therefore, it is possible to print ink having no coloring material at a suitable timing.

  Further, the first nozzle row may be arranged on the upstream side in the transport direction with respect to the second nozzle row, and the first nozzle row may be arranged more than the second nozzle row. It may be arranged on the downstream side in the transport direction, the first nozzle row is more upstream in the transport direction than the second nozzle row, and the first nozzle row is more than the second nozzle row It is arranged downstream in the transport direction, and the first nozzle row may appropriately discharge the ink having no color material.

A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
In the transport direction, the first nozzle row is disposed on at least one of an upstream side and a downstream side of the second nozzle row,
A print head in which the ink having no color material is ejected from the first nozzle row before the ink is ejected from the second nozzle row.
For this reason, it is possible to print the ink having no color material at a suitable timing as needed in the print head.

A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
In the transport direction, the first nozzle row is disposed on at least one of an upstream side and a downstream side of the second nozzle row,
A print head in which the ink having no color material is ejected from the first nozzle row after the ink is ejected from the second nozzle row.
Even in such a print head, it is possible to print ink having no color material at a suitable timing as needed.

Further, the following printing method can be realized.
A printing method,
Transporting the medium in the transport direction;
Discharging ink having no color material onto the medium;
Ejecting the ink having no coloring material onto the medium, and then ejecting the ink having the coloring material;
A printing method.

A printing method,
Transporting the medium in the transport direction;
Discharging ink having a color material onto a medium;
Ejecting the ink having the coloring material onto the medium, and then ejecting the ink having no coloring material;
Printing method having

=== First Embodiment ===
First, a first embodiment will be described with reference to FIGS. 1 to 8B.

  First, an overview of a printing apparatus and a printing computer system will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a printing computer system provided with an ink jet printer (hereinafter, abbreviated as “printer”) 22 as a printing apparatus. FIG. FIG. 4 is a block diagram illustrating a configuration example of a unit.

  As shown in FIG. 1, the printer 22 includes a sub-scanning feed mechanism as a transport mechanism that transports the printing paper P in the transport direction by a paper transport motor 23, and a carriage 31 that is moved in the axial direction of the paper transport roller 26 by a carriage motor 24. A reciprocating main scanning feed mechanism. Here, the feeding direction of the printing paper P by the sub-scanning feed mechanism is called a sub-scanning direction, and the moving direction of the carriage 31 by the main scanning feed mechanism is called a main scanning direction.

  The printer 22 includes a print head unit 60 mounted on the carriage 31 and including the print head 12, a head drive mechanism that drives the print head unit 60 to control ink ejection and dot formation, and paper The control circuit 40 is provided with a feed motor 23, a carriage motor 24, a print head unit 60, and a control circuit 40 which controls exchange of signals with the operation panel 32.

  The control circuit 40 is connected to the computer 90 via the connector 56.

      The computer 90 is equipped with a driver for the printer 22, accepts user commands by operating a keyboard, a mouse, or the like as an input device, and presents various information in the printer 22 on a screen display of a display device. Configure the interface.

  The sub-scan feed mechanism that transports the printing paper P includes a gear train (not shown) that transmits the rotation of the paper feed motor 23 to the paper feed roller 26 and the paper transport roller (not shown).

  The main scanning feed mechanism for reciprocating the carriage 31 has an endless drive between a carriage shaft 24 and a slide shaft 34 laid parallel to the axis of the paper feed roller 26 and slidably holding the carriage 31. A pulley 38 for stretching the belt 36 and a position detection sensor 39 for detecting the origin position of the carriage 31 are provided.

  As shown in FIG. 2, the control circuit 40 includes a CPU (Central Processing Unit) 41, a programmable ROM (P-ROM (Read Only Memory)) 43, a RAM (Random Access Memory) 44, and a character storing a dot matrix of characters. An arithmetic and logic circuit including a generator (CG (Character Generator)) 45 and an EEPROM (Electronically Erasable and Programmable ROM) 46 is configured.

  The control circuit 40 further drives an I / F dedicated circuit 50 which is an interface (I / F (Interface)) with an external motor or the like, and drives a print head unit 60 connected to the I / F dedicated circuit 50. And a motor drive circuit 54 for driving the paper feed motor 23 and the carriage motor 24.

  The I / F dedicated circuit 50 has a built-in parallel interface circuit and can receive the print signal PS supplied from the computer 90 via the connector 56.

Next, the configuration of the computer 90 will be described with reference to FIG.
As shown in FIG. 3, the computer 90 includes a CPU 91, a ROM 92, a RAM 93, an HDD (Hard Disk Drive) 94, a video circuit 95, an I / F 96, a bus 97, a display device 98, an input device 99, and an external storage device 100. Have been.

Here, the CPU 91 is a control unit that executes various types of arithmetic processing according to programs stored in the ROM 92 and the HDD 94 and controls each unit of the apparatus.
The ROM 92 is a memory that stores basic programs and data executed by the CPU 91. The RAM 93 is a memory for temporarily storing programs being executed by the CPU 91, data being calculated, and the like.
The HDD 94 is a recording device that reads data and programs recorded on a hard disk, which is a recording medium, in response to a request from the CPU 91, and records data generated as a result of arithmetic processing of the CPU 91 on the aforementioned hard disk.
The video circuit 95 is a circuit that executes a drawing process according to a drawing command supplied from the CPU 91, converts the obtained image data into a video signal, and outputs the video signal to the display device 98.

  The I / F 96 is a circuit that appropriately converts the expression format of the signal output from the input device 99 and the external storage device 100, and outputs a print signal PS to the printer 22.

  The bus 97 is a signal line that interconnects the CPU 91, the ROM 92, the RAM 93, the HDD 94, the video circuit 95, and the I / F 96, and enables data transmission and reception between them.

  The display device 98 is configured by, for example, an LCD (Liquid Crystal Display) monitor or a CRT (Cathode Ray Tube) monitor, and displays an image corresponding to a video signal output from the video circuit 95.

  The input device 99 is configured by, for example, a keyboard and a mouse, and is a device that generates a signal according to a user operation and supplies the signal to the I / F 96.

  The external storage device 100 includes, for example, a CD-ROM (Compact Disk-ROM) drive unit, an MO (Magneto Optic) drive unit, and an FDD (Flexible Disk Drive) unit. This is a device that reads out data and programs stored therein and supplies them to the CPU 91. In the case of the MO drive unit and the FDD unit, it is a device for recording data supplied from the CPU 91 on an MO disk or FD.

  Next, the configuration of the print head 12 will be described with reference to FIGS. 1, 4A, and 4B.

  As shown in FIG. 1, the carriage 31 includes a cartridge 71 containing black (K) ink, a cartridge 72 containing yellow (Y) ink, a cartridge 73 containing magenta (M) ink, and a cyan ( Five ink cartridges 71 to 75 including a cartridge 74 containing the ink C) and a cartridge 75 containing the clear (N) ink are removably mounted. Note that the compositions of the clear ink and the color ink differ depending on the application, and will be described later in detail.

  As shown in FIG. 1, the print head 12 is provided below the carriage 31. In the print head 12, as shown in FIG. 4A, nozzles as ink discharge locations are arranged in a row in the transport direction of the printing paper P, forming nozzle rows R1 to R5. The detailed configuration of the nozzle will be described later.

  In the nozzle rows R1 to R5 provided below the carriage 31 and associated with each ink, a piezo element, which is one of the electrostrictive elements and has excellent responsiveness, is arranged for each nozzle. The piezo element is installed at a position in contact with a member that forms an ink passage that guides ink to the nozzle. The crystal structure of a piezo element is distorted by the application of a voltage, and converts electric-mechanical energy very quickly.

  In the first embodiment, by applying a voltage having a predetermined time width between electrodes provided at both ends of the piezo element, the piezo element is extended by the voltage application time to deform one side wall of the ink passage. . As a result, the volume of the ink passage contracts in accordance with the expansion of the piezo element, and the ink corresponding to the contraction is ejected at high speed from the tip of the nozzle as an ink droplet. The ink droplets permeate the printing paper P along the paper feed roller 26 to form dots and perform printing.

  FIG. 4A is a diagram illustrating an arrangement of nozzles in the print head 12 (a diagram in which the nozzles 12 are viewed from the printing paper P side). As shown in the drawing, a nozzle row R1 for discharging black (K) ink is formed on the left side of the print head 12, and clear (N), yellow (Y), magenta (M), and cyan (C) inks are formed. Nozzle rows R2 to R5 for ejection are formed in this order in a row in the sub-operation direction. In addition, the nozzle row R2 forms a first nozzle row, and the nozzle rows R3 to R5 form a second nozzle row.

  FIG. 4B is a diagram illustrating a positional relationship between the nozzle rows R2 to R5 and the printing paper P during printing. As shown in this figure, the printing paper P is between the print head 12 and a platen (a member that is disposed at a position facing the printing head 12 and holds the printing paper P in a planar shape) from the right in the figure. The ink droplets are conveyed to the left, and are ejected in this order (in the order of NYMC) by the nozzle rows R2 to R5 of the print head 12. As is clear from FIG. 4A, the clear (N) ink is arranged at the most upstream side in the sub-scanning direction of the printing paper P, that is, at the leading side in the sub-scanning direction. Will be driven.

  Here, in FIG. 4A, each of the nozzle rows R1 to R5 is represented as one line segment, but each line segment is actually configured by arranging a plurality of nozzles in a row. Note that the nozzle row R1 and the nozzle rows R2 to R5 may not be arranged as shown in FIG. Also, the nozzle row R2 needs to be on the upstream side of the nozzle rows R3 to R5, but the order in which the nozzle rows R3 to R4 are arranged may be other than that shown in FIG. 4A.

  FIG. 5 is a diagram showing functional blocks of driver software for the printer 22 installed in the computer 90. As shown in this figure, the driver software includes a color conversion unit 120 and a half-toning unit 121, and the output of the half-toning unit 121 is supplied to each nozzle row.

  Here, the color conversion unit 120 receives input of image data such as, for example, RGB (Red, Green, Blue) full-color image data, and constitutes the input image data, for example, color data of an RGB color system. Is converted into CMY color data having color components corresponding to the color set of the color ink. Note that black (K) is used when printing text or the like, and is not used for color printing.

  The halftoning unit 121 performs processing such as error diffusion or dithering on the image data output from the color conversion unit 120, and converts multi-tone (for example, 256 tones) data of each CMY color into The data is converted into, for example, binarized bitmap data expressed by the dot density of each color of CMY. When printing a text, the character data is subjected to an error diffusion process, and is converted into binary bitmap data for K.

  Further, the halftoning unit 121 performs color printing, and when generating bitmap data, in addition to CMY dot data indicating CMY dots, N dot data indicating clear ink dots is also generated when generating bitmap data. Generate. For example, in the case of the above-mentioned (1-A) improvement of gloss unevenness, when one or a plurality of pixels are focused on, the N dot data indicates that the ejection amount of the color ink in the dot or the dot group is a predetermined amount. Is set so that clear ink is replenished so as to fall within the range. Note that the bitmap data output from the halftoning unit 121 includes the above-described C, M, Y, K, and N bitmap data.

  The bitmap data output from the half-toning unit 121 is supplied to the print head 12, and when printing an image, C, M, Y, and N ink droplets are ejected according to the bitmap data, and when printing text, Is ejected, and a dot is formed on the printing paper P.

  Next, in the case of (2-A) described above for the operation of the first embodiment, that is, the clear ink is formed in advance of the color ink before the dot is formed in order to prevent bleeding or the like. A description will be given by taking as an example the case of driving a part or its vicinity.

In the case of (2-A), as the clear ink, one obtained by dissolving a transparent polymer in water as a solvent is used. In addition, as the color ink, one obtained by dissolving each color pigment in water as a solvent is used.
When a request to start the application program is made by operating the input device 99 of the computer 90, the CPU 91 reads the relevant program from the HDD 94 and executes it. As a result, the application program is activated, and generation or editing of image data becomes possible.
When a request to print the generated image is made via the input device 99 after the image is drawn or edited using such an application program, the CPU 91 converts the generated image data into Supply to driver software.

The image data is data represented by the RGB color system, and is, for example, image data having a resolution of 360 dpi (Dots Per Inch) in the vertical and horizontal directions.
The color conversion unit 120 constituting the driver software converts the image data passed from the application program into CMY color image data. In this conversion process, for example, an LUT (Look Up Table) stored in the HDD 94 is used.

  When the conversion to the CMY color system is completed, the color conversion unit 120 performs an error diffusion process or a dithering process on the CMY color system image data (256 gradation data) obtained as a result of the conversion. , CMY are generated for each color. At this time, the resolution of the image is converted from a vertical / horizontal 360 × 360 dpi at the time of input to a vertical / horizontal 720 × 720 dpi corresponding to the resolution of the print head 12.

  The half-toning unit 121 is configured such that, for example, when one of the pixels of the color ink adjacent in the vertical direction (sub-scanning direction) of the pixel of the clear ink is “1”, that is, any of the CMY inks When the ink is to be applied, clear ink is applied in advance (bitmap data is set to "1"). If both of the adjacent color ink pixels are "0", that is, if none of the CMY is applied, no clear ink is applied (bitmap data is set to "0").

  More specifically, as shown in FIG. 6, when the resolution of the color ink is 720 dpi in the vertical and horizontal directions and the resolution of the clear ink is 360 dpi and 720 dpi in the vertical and horizontal directions, the dots 201 and 202 corresponding to the color inks are displayed. When at least one of the dots (shown by a black circle in FIG. 6) is “1”, the dot 203 (shown by a white circle in FIG. 6) corresponding to the clear ink is set to “1”, and when both are “0”. , The dot 203 corresponding to the clear ink is set to “0”.

  The bitmap data of the color ink and the clear ink thus generated are output from the halftoning unit 121 and supplied to the printer 22 via the I / F unit 96. In the printer 22, the CPU 41 receives these data. The CPU 41 drives the paper feed motor 23 to suck only one print sheet P and transfers it to the printing start position. When the printing start position of the printing paper P has moved to just below the printing head 12, the received bitmap data is supplied to the printing head 12 via the head driving circuit 52, and printing is started. At this time, the bitmap data of the clear ink is supplied to the nozzle row R2 of the print head 12, and the other bitmap data is supplied to the nozzle rows R3 to R5 for each color.

  When printing is started, the CPU 41 discharges the clear ink from the nozzle row R2 and the color ink from the nozzle rows R3 to R5 while scanning the carriage 31 in the main scanning direction, and prints the printing paper P in the sub-scanning direction. The operation of intermittent conveyance is repeated. At this time, first, the clear (N) ink is applied to the printing paper P, and then the color inks are applied in the order of Y, M, and C, and the respective hues are superposed. As a result, since the color ink is injected after the clear ink has been injected and the characteristics of the printing paper P have been improved, it is possible to prevent bleeding and to improve the coloring, fixing, or drying properties. Become.

  As described above, in the present embodiment, the clear ink is previously applied to the area where the color ink is applied, so that the bleeding prevention, the color development, the fixability, or the drying property of the portion can be improved. Becomes possible. Further, since the nozzle row R2 is arranged at the most upstream side of the print head 12, the color ink is printed after the clear ink is sufficiently fixed and the characteristics of the printing paper P are improved, so that the effect of the clear ink is obtained. Can be fully exhibited.

  In the above-described first embodiment, the clear ink is ejected when any of adjacent upper and lower (sub-scanning direction) color ink dots is ejected. However, besides this, for example, the clear ink may be applied to an area where the density of the applied color ink is high, or the entire area may be uniformly applied.

=== Second Embodiment ===
Next, a second embodiment of the present invention will be described. In the second embodiment, only the configuration of the print head 12A is different from the print head 12 of the first embodiment. Therefore, only the configuration of the print head 12A will be described.

  FIG. 7 is a diagram illustrating a configuration example of a print head 12A according to another embodiment of the present invention. As shown in this figure, in this embodiment, nozzle rows Ra1 to Ra6 are arranged side by side in the main scanning direction. Specifically, nozzle rows Ra1 to Ra6 are arranged from left to right in FIG. 7, the nozzle rows Ra1 and Ra6 are clear (N) ink, and the nozzle rows Ra2 to Ra5 are cyan (C) and It corresponds to magenta (M), yellow (Y), and black (K) inks. Further, in this embodiment, when the print head 12A reciprocates in the main scanning direction, printing is performed on both the forward path and the return path. Note that the nozzle rows Ra2 to Ra5 constitute a second nozzle row, and the nozzle rows Ra1 and Ra6 constitute a first nozzle row.

Next, the operation of the above-described second embodiment will be described.
In the second embodiment, the operations of the color conversion unit 120 and the halftoning unit 121 shown in FIG. 5 are the same as those in the above-described embodiment, but the procedure for discharging ink by the print head 12A is different. ing. Therefore, the operation of ejecting ink by the print head 12A will be described with reference to (2-A) as an example.

In the case of (2-A), bitmap data for clear ink and color ink is generated by the same processing as described above, and is supplied to the printer 22. The printer 22 supplies the bitmap data received from the computer 90 to the nozzle rows Ra2 to Ra5 for each color, and drives the carriage motor 24 to perform a printing process.
More specifically, when the carriage 31 is moved (scanned) in the outward direction shown in FIG. 7, printing is performed using only the nozzle rows Ra2 to Ra6 without using the nozzle row Ra1. That is, in the printing in the forward direction, after the clear ink is printed by the nozzle row Ra6, the color ink is ejected and printed in the order of the nozzle rows Ra5, Ra4, Ra3, and Ra2 to the portion where the clear ink is applied. .

On the other hand, on the return path, printing is performed using only the nozzle rows Ra1 to Ra5 without using the nozzle row Ra6. That is, in the printing in the backward direction, after the clear ink is ejected by the nozzle row Ra1, the color ink is ejected and printed in the order of the nozzle rows Ra2, Ra3, Ra4, and Ra5.
Then, by repeating such a reciprocating operation, the color ink and the clear ink are applied on the printing paper P, and the printing of the image is completed.

According to the above-described second embodiment, the clear ink is printed using the nozzle row Ra6 on the outward pass, and the printing is performed using the nozzle row Ra1 on the return pass. Can be printed earlier.
Therefore, since the color ink can be printed after the clear ink is sufficiently fixed on the printing paper P, it is possible to improve the color developability and the like.

  In the above-described second embodiment, an example has been described in which printing is performed on both the forward path and the return path of the carriage 31. However, for example, a printer that performs printing only in one direction of the forward path or the return path is described. The present invention can also be applied to such cases. For example, when printing is performed only on the outward path, the nozzle row Ra1 is not provided, and printing is performed only by the nozzle rows Ra2 to Ra6. After printing of the clear ink by the nozzle row Ra6 is completed, the printing is performed by the nozzle rows Ra2 to Ra5. What is necessary is just to print color ink. Conversely, when printing is performed only on the return path, the nozzle row Ra6 is not provided, printing is performed only with the nozzle rows Ra1 to Ra5, and after the clear ink is printed using the nozzle row Ra1, the color is printed using the nozzle rows Ra2 to Ra5. What is necessary is just to print ink.

  Although the first and second embodiments of the present invention have been described above, the present invention can be variously modified in addition to the above. For example, as the ink, four colors of CMYK are used, but in addition to this, light color inks (light cyan (LC), light magenta (LM), dark yellow (DY)) may be used. Good.

  In the first and second embodiments, when printing an image, three colors of CMY are used. However, as described above, a light-colored ink is used, and a black (K) ink is used. Can also be used. In this case, when the nozzle configuration having the same arrangement as that of the embodiment shown in FIG. 4A is employed, the nozzle row R1 has a range corresponding to the nozzle rows R2 to R4 as in the print head 12B shown in FIG. 8A. By performing printing using only the nozzle group of No. and not using the nozzle group in the range corresponding to the nozzle row R5, it is possible to discharge clear ink after discharging black (K) ink. . Alternatively, as in the case of the print head 12C shown in FIG. 8B, it is possible not to provide the nozzle group in the range corresponding to the nozzle row R5 in the print head 12.

  Further, the composition of the ink has been described with reference to specific examples, but the present invention is not limited to the specific examples.

  In addition, as described above, the printer 22 including the head that discharges ink using the piezo element is used. However, as the discharge driving element, various types other than the piezo element can be used. For example, the present invention can be applied to a printer including a discharge drive element of a type in which a heater disposed in an ink passage is energized and ink is discharged by bubbles generated in the ink passage.

    Further, in the first and second embodiments described above, the processing of the color conversion unit 120 and the halftoning unit 121 is executed by the driver software stored in the HDD 94 (or the external storage device 100). However, a program having equivalent functions is stored in the P-ROM 43 of the printer 22, and the processing of the color conversion unit 120 and the halftoning unit 121 is executed by this program. It is also possible to share and process.

=== Third Embodiment ===
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. First, a third embodiment will be described with reference to FIGS.

  First, an overview of a printing apparatus and a printing computer system will be described with reference to FIGS. FIG. 10 is a schematic configuration diagram of a printing computer system including an ink jet printer (hereinafter, abbreviated to “printer”) 1022 as a printing apparatus. FIG. FIG. 4 is a block diagram illustrating a configuration example of a unit.

  As shown in FIG. 10, the printer 1022 includes a sub-scanning feed mechanism as a transport mechanism for transporting the printing paper P in the transport direction by a paper transport motor 1023, and a carriage 1031 by a carriage motor 1024 in the axial direction of the paper transport roller 1026. A reciprocating main scanning feed mechanism. Here, the feed direction of the printing paper P by the sub-scan feed mechanism is called a sub-scan direction, and the moving direction of the carriage 1031 by the main scan feed mechanism is called a main scan direction.

  The printer 1022 is mounted on a carriage 1031 and includes a print head unit 1060 having a print head 1012; a head drive mechanism that drives the print head unit 1060 to control ink ejection and dot formation; A control circuit 1040 for controlling the exchange of signals with the feed motor 1023, the carriage motor 1024, the print head unit 1060, and the operation panel 1032 is provided.

The control circuit 1040 is connected to a computer 1090 via a connector 1056.
The computer 1090 is provided with a driver for the printer 1022, accepts a user's instruction by operating a keyboard, a mouse, or the like as an input device, and presents various information in the printer 1022 on a screen of a display device. Configure the interface.
The sub-scan feed mechanism that transports the printing paper P includes a gear train (not shown) that transmits the rotation of the paper transport motor 1023 to the paper transport roller 1026 and the paper transport roller (not shown).
A main scanning feed mechanism for reciprocating the carriage 1031 includes an endless drive between a carriage shaft 1024, which is laid in parallel with the axis of the paper feed roller 1026, and slidably holds the carriage 1031. A pulley 1038 for stretching the belt 1036 and a position detection sensor 1039 for detecting the origin position of the carriage 1031 are provided.

  As shown in FIG. 11, the control circuit 1040 includes a CPU (Central Processing Unit) 1041, a programmable ROM (P-ROM (Read Only Memory)) 1043, a RAM (Random Access Memory) 1044, and a character storing a dot matrix of characters. It is configured as an arithmetic and logic operation circuit including a generator (CG (Character Generator)) 1045 and an EEPROM (Electronically Erasable and Programmable ROM) 1046.

The control circuit 1040 further drives an I / F dedicated circuit 1050 which is an interface (I / F (Interface)) with an external motor or the like, and a print head unit 1060 connected to the I / F dedicated circuit 1050. And a motor drive circuit 1054 for driving the paper feed motor 1023 and the carriage motor 1024.
The I / F dedicated circuit 1050 has a built-in parallel interface circuit, and can receive the print signal PS supplied from the computer 1090 via the connector 1056.

Next, the configuration of the computer 1090 will be described with reference to FIG.
As shown in FIG. 12, the computer 1090 includes a CPU 1091, a ROM 1092, a RAM 1093, a hard disk drive (HDD) 1094, a video circuit 1095, an I / F 1096, a bus 1097, a display device 1098, an input device 1099, and an external storage device 1100. Have been.

Here, the CPU 1091 is a control unit that executes various arithmetic processes according to programs stored in the ROM 1092 and the HDD 1094 and controls each unit of the apparatus.
The ROM 1092 is a memory that stores basic programs and data executed by the CPU 1091. The RAM 1093 is a memory for temporarily storing programs being executed by the CPU 1091, data being operated on, and the like.
The HDD 1094 is a recording device that reads out data and programs recorded on a hard disk as a recording medium in response to a request from the CPU 1091 and records data generated as a result of arithmetic processing of the CPU 1091 on the aforementioned hard disk.
The video circuit 1095 is a circuit that executes a drawing process according to a drawing command supplied from the CPU 1091, converts the obtained image data into a video signal, and outputs the video signal to the display device 1098.
The I / F 1096 is a circuit that appropriately converts the expression format of the signal output from the input device 1099 and the external storage device 1100, and outputs a print signal PS to the printer 1022.
The bus 1097 is a signal line that connects the CPU 1091, the ROM 1092, the RAM 1093, the HDD 1094, the video circuit 1095, and the I / F 1096 to each other, and enables data transmission and reception among them.
The display device 1098 includes, for example, an LCD (Liquid Crystal Display) monitor and a CRT (Cathode Ray Tube) monitor, and is a device that displays an image corresponding to a video signal output from the video circuit 1095.
The input device 1099 is configured by, for example, a keyboard and a mouse, and is a device that generates a signal according to a user operation and supplies the signal to the I / F 1096.

  The external storage device 1100 includes, for example, a CD-ROM (Compact Disk-ROM) drive unit, an MO (Magneto Optic) drive unit, and an FDD (Flexible Disk Drive) unit, and is recorded on a CD-ROM disk, an MO disk, and an FD. This is a device that reads out data and programs stored therein and supplies them to the CPU 1091. In the case of the MO drive unit and the FDD unit, it is a device for recording data supplied from the CPU 1091 on an MO disk or FD.

  Next, the configuration of the print head 1012 will be described with reference to FIGS. 10, 13A, and 13B.

  As shown in FIG. 10, the carriage 1031 includes a cartridge 1071 containing black (K) ink, a cartridge 1072 containing yellow (Y) ink, a cartridge 1073 containing magenta (M) ink, and cyan ( Five ink cartridges 1071 to 1075, a cartridge 1074 containing the ink C) and a cartridge 1075 containing the clear (N) ink, are removably mounted. Note that the compositions of the clear ink and the color ink differ depending on the application, and will be described later in detail.

  As shown in FIG. 10, a print head 1012 is provided below the carriage 1031. In the print head 1012, as shown in FIG. 13A, nozzles as ink discharge locations are arranged in a row in the transport direction of the printing paper P, forming nozzle rows R1 to R5. The detailed configuration of the nozzle will be described later.

  In the nozzle rows R1 to R5 provided below the carriage 1031 and associated with each ink, a piezo element, which is one of the electrostrictive elements and has excellent responsiveness, is arranged for each nozzle. The piezo element is installed at a position in contact with a member that forms an ink passage that guides ink to the nozzle. The crystal structure of a piezo element is distorted by the application of a voltage, and converts electric-mechanical energy very quickly.

  In the third embodiment, by applying a voltage having a predetermined time width between the electrodes provided at both ends of the piezo element, the piezo element is extended by the voltage application time and one side wall of the ink passage is deformed. As a result, the volume of the ink passage contracts in accordance with the expansion of the piezo element, and the ink corresponding to the contraction is ejected at high speed from the tip of the nozzle as an ink droplet. The ink droplets permeate the printing paper P along the paper feed roller 1026 to form dots and perform printing.

  FIG. 13A is a diagram illustrating an arrangement of nozzles in the print head 1012 (a diagram in which the nozzles 1012 are viewed from the printing paper P side). As shown in the figure, a nozzle row R1 for discharging black (K) ink is formed on the left side of the print head 1012, and yellow (Y), magenta (M), cyan (C), and clear (N) inks are formed. The nozzle rows R2 to R5 for discharging are formed in this order in a row in the sub-operation direction. The nozzle rows R2 to R4 form a second nozzle row, and the nozzle row 5 forms a first nozzle row.

  FIG. 13B is a diagram illustrating a positional relationship between the nozzle rows R2 to R5 and the printing paper P during printing. As shown in this figure, the print paper P is placed between the print head 1012 and a platen (a member that is disposed at a position facing the print head 1012 and holds the print paper P in a flat shape) from the right in the figure. The ink droplets are conveyed to the left, and are ejected by the nozzle rows R2 to R5 of the print head 1012 in this order (YMCN order). As is clear from FIG. 13A, the clear (N) ink is arranged at the most downstream side in the sub-scanning direction of the printing paper P, that is, at the end side in the sub-scanning direction. Will be driven.

  Here, in FIG. 13A, each of the nozzle rows R1 to R5 is represented as one line segment, but each line segment is actually configured by arranging a plurality of nozzles in a row. It should be noted that the nozzle row R1 and the nozzle rows R2 to R5 may not be arranged as shown in FIG. Further, the nozzle row R5 needs to be on the downstream side of the nozzle rows R2 to R4, but the order in which the nozzle rows R2 to R4 are arranged may be other than that shown in FIG. 13A.

  FIG. 14 is a diagram showing functional blocks of driver software for the printer 1022 installed in the computer 1090. As shown in this figure, the driver software includes a color conversion unit 1120 and a half-toning unit 1121, and the output of the half-toning unit 1121 is supplied to each nozzle row.

  Here, the color conversion unit 1120 receives input of image data such as, for example, RGB (Red, Green, Blue) full-color image data, and constitutes the input image data, for example, color data of an RGB color system. Is converted into CMY color data having color components corresponding to the color set of the color ink. Note that black (K) is used when printing text or the like, and is not used for color printing.

  The half-toning unit 1121 performs processing such as error diffusion or dithering on the image data output from the color conversion unit 1120, and converts multi-tone (for example, 256 tones) data of each CMY color into The data is converted into, for example, binarized bitmap data expressed by the dot density of each color of CMY. When printing a text, the character data is subjected to an error diffusion process, and is converted into binary bitmap data for K.

  The halftoning unit 1121 performs color printing, and when generating bitmap data, the half-toning unit 1121 also generates N dot data indicating clear ink dots in addition to CMY dot data indicating CMY dots. Generate. For example, in the case of the above-mentioned (1-A) improvement of gloss unevenness, when one or a plurality of pixels are focused on, the N dot data indicates that the ejection amount of the color ink in the dot or the dot group is a predetermined amount. Is set so that clear ink is replenished so as to fall within the range. The bitmap data output from the halftoning unit 1121 includes the above-described bitmap data of C, M, Y, K, and N.

  The bitmap data output from the half-toning unit 1121 is supplied to the print head 1012, and when printing an image, C, M, Y, and N ink droplets are ejected according to the bitmap data, and when printing a text. Is ejected, and a dot is formed on the printing paper P.

  Next, the operation of the third embodiment will be described. In the following, first, an operation corresponding to the above-described “1-A)“ improvement of gloss unevenness ”will be described, and then“ 1-2) “improvement of gloss unevenness” and (3) will be described. The operation in the case of "improving the printing speed" will be described.

First, the operation in the case where clear ink is ejected to a portion having a low dot density in order to improve the gloss unevenness of (1-A) will be described.
In the case of (1-A), a clear polymer obtained by dissolving a transparent polymer in water as a solvent is used. In addition, as the color ink, one obtained by dissolving each color pigment in water as a solvent is used.
When a request to start the application program is made by operating the input device 1099 of the computer 1090, the CPU 1091 reads the relevant program from the HDD 1094 and executes it. As a result, the application program is activated, and generation or editing of image data becomes possible.
After the image is drawn or edited using such an application program, if a request to print the generated image is made via the input device 1099, the CPU 1091 converts the generated image data into Supply to driver software.
The image data is data represented by the RGB color system, and is, for example, image data having a resolution of 360 dpi (Dots Per Inch) in the vertical and horizontal directions.
The color conversion unit 1120 included in the driver software converts the image data passed from the application program into CMY color image data. In this conversion process, for example, an LUT (Look Up Table) stored in the HDD 1094 is used.

  When the conversion into the CMY color system is completed, the color conversion unit 1120 performs an error diffusion process or a dithering process on the image data (256 gradation data) of the CMY color system obtained as a result of the conversion. , CMY are generated for each color. At this time, the resolution of the image is converted from vertical / horizontal 360 × 360 dpi at the time of input to vertical / horizontal 720 × 720 dpi corresponding to the resolution of the print head 1012.

  Further, the halftoning unit 1121 generates bitmap data for clear ink so that dots of clear ink are formed in a portion where the density of dots of color ink is low. That is, when focusing on all the inks of CMY and N, the half-toning unit 1121 clears the ink amount (mass or volume) that lands per unit area in each part of the printing paper P so as to be within a certain range. Generate bitmap data for ink. The amount of the clear ink to be applied is appropriately set according to the glossiness of the dots formed by the clear ink and the actual gloss unevenness at the time of printing.

  Note that the glossiness per the same amount is higher for the clear ink, so it is not necessary to apply the same amount of the clear ink as the color ink. Therefore, the resolution of the clear ink bitmap data may be set to be lower than 720 dpi in each of the vertical and horizontal directions. In short, there is no problem as long as the resolution is such that clear ink can be ejected so as to satisfy the above requirements.

Curve More specifically, for example, when attention is paid to one or more pixels, indicating the total ejection amount of CMY ink with respect to the pixel (s) When D _CMY, 15 in accordance with the applying amount D _CMY The discharge amount of the clear ink is determined based on. That is, when the _DCMY is small, the discharge amount of the clear ink (or the density of the formed dots) is increased, and when the _DCMY is large, the discharge amount of the clear ink (or the density of the formed dots) is increased. Decrease. Further, when generating one bitmap data for clear ink, by increasing or decreasing the number of pixels of interest, the resolution of the bitmap data for clear ink can be changed.

  The bitmap data of the color ink and the clear ink thus generated is output from the halftoning unit 1121 and supplied to the printer 1022 via the I / F unit 1096. In the printer 1022, the CPU 1041 receives these data. The CPU 1041 drives the paper feed motor 1023 to suck only one sheet of the printing paper P, and transports it to the printing start position. When the printing start position of the printing paper P has moved to just below the printing head 1012, the received bitmap data is supplied to the printing head 1012 via the head driving circuit 1052, and printing is started. At this time, the bitmap data of the clear ink is supplied to the nozzle row R5 of the print head 1012, and the other bitmap data is supplied to the nozzle rows R2 to R4 for each color.

  When printing is started, the CPU 1041 ejects the color ink from the nozzle rows R2 to R4 and the clear ink from the nozzle row R5 while scanning the carriage 1031 in the main scanning direction, and prints the printing paper P in the sub-scanning direction. The operation of intermittent conveyance is repeated. At this time, for the color inks, after the inks are printed in the order of Y, M, and C, and the respective hues are superimposed, N ink is finally printed. As a result, since the clear ink is printed after the color ink is sufficiently fixed, the influence of the clear ink on the color ink can be reduced, and good color development can be obtained.

FIG. 16 is a schematic diagram of a cross section of the printing paper P printed according to this embodiment.
As shown in FIG. 16, dots 1220 made of color ink are formed on the surface of the printing paper P, and dots 1221 made of clear ink are formed in an area where the color ink does not adhere or an area where the amount of the color ink is small. Is formed. Accordingly, the amount of ink adhered on the surface of the printing paper P becomes substantially uniform, and the difference in light reflectance, that is, the unevenness in gloss is reduced. This drawing is a schematic diagram, and as shown in this drawing, the clear ink is not necessarily applied to all areas where the color ink is not applied.

  As described above, in the third embodiment, the clear ink is replenished in an area where the amount of the color ink to be applied is small. Can be prevented. Further, since the nozzle row R5 is disposed at the most downstream side of the print head 1012, the clear ink is printed after the color ink is sufficiently fixed, so that the influence of the clear ink on the color ink can be reduced. And good color development can be obtained.

  In addition, since the clear ink generally has a higher gloss than the same amount of color ink, the number of nozzle groups constituting the nozzle row R5 is smaller than that of the color ink nozzle rows R2 to R4. Even in this case, it is possible to sufficiently improve uneven gloss. Further, even when the glossiness of the clear ink is equal to or lower than that of other inks, it can be dealt with by increasing the ejection amount.

In the third embodiment described above, the position and amount of the clear ink are determined such that the total amount of the color ink and the clear ink to be applied per unit area is within a predetermined range in any region of the image. I did it. However, as described above, since gloss unevenness is particularly prominent near the boundary between a portion where color ink is applied and a portion where color ink is not applied, clear ink may be applied around the relevant portion. It is possible. Specifically, the above-described _DCMY is obtained for the entire image data, the obtained two-dimensional data is spatially differentiated, and a region having a large value and a region having a small _DCMY value (portion where color ink is applied) It is also possible to discharge clear ink into the area adjacent to the ink. This makes it possible to effectively prevent the occurrence of gloss unevenness and to suppress the consumption of the clear ink.

Next, an operation corresponding to (1-B), that is, an operation in which clear ink is applied to the entire image in "improvement of gloss unevenness" to perform so-called uniform overcoating will be described.
In the case of (1-B), as the clear ink, an overcoat liquid having a film forming ability, for example, a liquid obtained by dissolving a transparent polymer in water as a solvent is used.
In addition, as the color ink, one obtained by dissolving each color pigment in water as a solvent is used.

For (1-B), since implanted uniformly clear ink over the entire image, generates bitmap data for the clear ink according to D _CMY by way halftoning unit 1121 of the processing of (1-A) No need to do. That is, in this case, the bit map data for clear ink may be fixed data such that the bit for clear ink becomes "1" at predetermined intervals.

More specifically, in the case of (1-B), the halftoning unit 1121 generates bitmap data that becomes “1” at regular intervals regardless of the state of the CMY pixels, and supplies the bitmap data to the nozzle row R5. Is done.
In the printer 1022, color ink is ejected from the nozzle rows R2 to R4 according to the CMY bitmap data supplied from the half-toning unit 1121, and the color layers are superimposed on the printing paper P in the order of CMY. . Then, after each of the CMY inks is sufficiently fixed on the printing paper P, the clear ink is ejected from the nozzle row R5 from above these dots and overcoated.
Other operations are the same as in the case of (1-A).

  As described above, according to the present embodiment, after each of the CMY inks is sufficiently fixed on the printing paper P, the clear ink is discharged from the nozzle row R5 from above these dots and overcoated. As a result, the unevenness in gloss can be surely eliminated, and the color ink is protected by the film formed by the clear ink, so that the light resistance can be increased.

Next, the operation in the case of (3) “improving printing speed” will be described.
In the case corresponding to “improvement of printing speed” in (3), the composition of the color ink and the clear ink is different from that in the case of “improvement in gloss unevenness” in (1-A) described above. 1121 is different. Therefore, the following description focuses on the composition of the ink and the operation of the half-toning unit 1121.

First, in the case of (3) “improvement of printing speed”, as the color ink, for example, an aqueous ink containing a coloring material is used, and as the clear ink, for example, water as a solvent is used.
Further, in the case of “1-A)“ improvement in gloss unevenness ”, clear ink is applied to an area where color ink is not applied. In such a case, it is necessary to apply clear ink to an area where solid ink is applied and an area where solid printing is performed.
Therefore, in the case of (3), when generating the clear ink bitmap data, the halftoning unit 1121 first specifies an area where solid printing is to be performed, and in the specified area, the clear ink pixel When one of the pixels of the color ink adjacent in the vertical direction (sub-scanning direction) is “1”, that is, when any of the CMY inks is applied, the clear ink is applied (the bitmap data is "1"). If both of the adjacent color ink pixels are "0", that is, if none of the CMY is applied, no clear ink is applied (bitmap data is set to "0").

  More specifically, as shown in FIG. 17, when the resolution of the color ink is 720 dpi in the vertical and horizontal directions, and the resolution of the clear ink is 360 dpi and 720 dpi in the vertical and horizontal directions, the dots 1201 and 1202 corresponding to the color inks are displayed. If at least one of the dots (shown by black circles in FIG. 17) is “1”, the dot 1203 (shown by white circles in FIG. 17) corresponding to the clear ink is set to “1”, and both are “0”. , The dot 1203 corresponding to the clear ink is set to “0”.

  The bitmap data of the color ink and the clear ink thus generated is supplied to the printer 1022, and the color inks are ejected from the nozzle rows R2 to R4 in the order of CMY, and the color layers are superimposed on the printing paper P. Subsequently, clear ink is ejected from the nozzle row R5.

  As a result, by ejecting the clear ink in the vicinity of the previously ejected color ink, the dots of the color ink can be intentionally blurred to enlarge the dot size. Can be solid printed. Further, since it is not necessary to repeatedly print, the printing speed can be improved.

=== Fourth Embodiment ===
Next, a fourth embodiment of the present invention will be described. In this embodiment, since the configuration of the print head 1012A is different from that of the third embodiment, only the configuration of the print head 1012A will be described.

  FIG. 18 is a diagram illustrating a configuration example of a print head 1012A according to the fourth embodiment of the present invention. As shown in this figure, in this embodiment, nozzle rows Ra1 to Ra6 are arranged side by side in the main scanning direction. Specifically, nozzle rows Ra1 to Ra6 are arranged from left to right in FIG. 18, the nozzle rows Ra1 and Ra6 are clear (N) ink, and the nozzle rows Ra2 to Ra5 are cyan (C) and It corresponds to magenta (M), yellow (Y), and black (K) inks. In this embodiment, when the print head 1012A reciprocates in the main scanning direction, printing is performed on both the outward path and the return path. Note that the nozzle rows Ra2 to Ra5 constitute a second nozzle row, and the nozzle rows Ra1 and Ra6 constitute a first nozzle row.

Next, the operation of the above-described fourth embodiment will be described.
In the fourth embodiment, the operations of the color conversion unit 1120 and the halftoning unit 1121 shown in FIG. 14 are the same as those in the above-described embodiment, but the procedure for ejecting ink by the print head 1012A is different. ing. Therefore, the operation of ejecting ink by the print head 1012A will be described for each case.

  First, in the case of (1-A), bitmap data for clear ink and color ink is generated by the same processing as described above, and is supplied to the printer 1022. The printer 1022 supplies the bitmap data received from the computer 1090 to the nozzle rows Ra2 to Ra5 for each color, and drives the carriage motor 1024 to perform a printing process.

  Specifically, when the carriage 1031 is moved (scanned) in the outward direction shown in FIG. 18, printing is performed using only the nozzle rows Ra1 to Ra5 without using the nozzle row Ra6. That is, in the printing in the forward direction, after the color ink is printed in the order of the nozzle rows Ra5, Ra4, Ra3, and Ra2, the clear ink is ejected from the nozzle row Ra1 to the portion where the color ink is sparse and printed.

On the other hand, on the return path, printing is performed using only the nozzle rows Ra2 to Ra6 without using the nozzle row Ra1. That is, in the printing in the backward direction, after the color ink is printed in the order of the nozzle rows Ra2, Ra3, Ra4, and Ra5, the clear ink is ejected from the nozzle row Ra6 to the portion where the color ink is sparse and printed.
Then, by repeating such a reciprocating operation, the color ink and the clear ink are applied on the printing paper P, and the printing of the image is completed.

  According to the above-described fourth embodiment, the clear ink is printed using the nozzle row Ra1 on the outward pass, and the printing is performed using the nozzle row Ra6 on the return pass. Can also be printed later. Therefore, after the color ink is sufficiently fixed, the clear ink can be printed, so that the color developability and the like can be improved.

Next, the operation in the case of (1-B) will be described.
In the case of (1-B), as in the case described above, since the clear ink needs to be uniformly applied to the entire image, the bitmap data in which the data is "1" at regular intervals is provided. Apply clear ink using.
In the printing operation, as in the case described above, printing is performed using the nozzle rows Ra1 to Ra5 in the case of the outward path, and printing is performed using the nozzle rows Ra2 to Ra6 in the case of the return path.
According to the fourth embodiment, since the clear ink can be uniformly overcoated after the color ink is applied, the gloss unevenness can be reliably reduced.

Next, an operation in a case corresponding to (2-B) "improvement of ink bleeding or the like" and (3) "improvement of printing speed" will be described.
In the case of (2-B) and (3), unlike the case of (1-A), the point that bitmap data is formed so that clear ink is applied to a pixel where color ink is applied or in the vicinity thereof. Is different. In the case of (3), the operation is performed only for an area where solid printing is performed.
In the printing operation, as in the case described above, printing is performed using the nozzle rows Ra1 to Ra5 in the case of the outward path, and printing is performed using the nozzle rows Ra2 to Ra6 in the case of the return path.
According to such an embodiment, in the case of (2-B), the clear ink is ejected in the vicinity of the dot formed by the color ink, so that blurring of the ruled line and the like can be improved.
In the case of (3), the clear ink is injected into the vicinity of the dot formed by the color ink, thereby causing bleeding and improving the printing speed.

  In the above-described fourth embodiment, an example has been described in which printing is performed on both the forward path and the return path of the carriage 1031. However, for example, a printer that performs printing only in one direction of the forward path or the return path is described. The present invention can also be applied to such cases. For example, when printing is performed only on the outward path, the nozzle row Ra6 is not provided, and printing is performed only by the nozzle rows Ra1 to Ra5, and after the printing of the color ink by the nozzle rows Ra2 to Ra5 is completed, the printing is performed by the nozzle row Ra1. What is necessary is just to print ink. Conversely, in the case of a printer that performs printing only on the return path, the nozzle array Ra1 is not provided, and printing is performed using only the nozzle arrays Ra2 to Ra6. What is necessary is just to print clear ink by Ra6.

  Although the third and fourth embodiments of the present invention have been described above, the present invention can be variously modified in addition to the above. For example, as the ink, four colors of CMYK are used, but in addition to this, light color inks (light cyan (LC), light magenta (LM), dark yellow (DY)) may be used. Good.

  In the third and fourth embodiments, when printing an image, three colors of CMY are used. However, as described above, a light-colored ink is used, and black (K) ink is used. It is also possible. In this case, in a case where a nozzle configuration having the same arrangement as that of the embodiment shown in FIG. 13A is employed, the nozzle row R1 has a range corresponding to the nozzle rows R2 to R4 as in a print head 1012B shown in FIG. 19A. By performing printing using only the nozzle groups of No. and not using the nozzle groups in the range corresponding to the nozzle row R5, it is possible to discharge clear ink after discharging black (K) ink. . Alternatively, as in the case of a print head 1012C shown in FIG. 19B, it is also possible not to provide the nozzle group in the range corresponding to the nozzle row R5 in the print head 1012.

  Further, the composition of the ink has been described with reference to specific examples, but the present invention is not limited to the specific examples.

  In addition, as described above, the printer 1022 including the head that discharges ink using the piezo element is used. However, as the discharge driving element, various devices other than the piezo element can be used. For example, the present invention can be applied to a printer including a discharge drive element of a type in which a heater disposed in an ink passage is energized and ink is discharged by bubbles generated in the ink passage.

  Furthermore, in the third and fourth embodiments, the processing of the color conversion unit 1120 and the halftoning unit 1121 is executed by driver software stored in the HDD 1094 (or the external storage device 1100). However, a program having equivalent functions is stored in the P-ROM 1043 of the printer 1022, and the processing of the color conversion unit 1120 and the half-toning unit 1121 is executed by this program. It is also possible to share and process.

=== Fifth Embodiment ===
Next, a fifth embodiment of the present invention will be described.
Also in the printing apparatus according to the fifth embodiment, the nozzle rows R2 to R4 for discharging the yellow (Y), magenta (M), and cyan (C) inks constitute the second nozzle row, and clear ( N) The nozzle row 5 for ejecting ink constitutes a first nozzle row.
Here, in the fifth embodiment, the first nozzle row is arranged upstream and downstream of the second nozzle row in the medium transport direction.
Then, ink (clear ink) having no color material is appropriately ejected from these first nozzle rows.

  In the fifth embodiment, for example, when using clear ink, which is preferably ejected before color ink, first, clear (N) ink is injected into the printing paper P from the first nozzle row. After that, the color inks are ejected in the order of Y, M and C, and the respective hues are superimposed. As a result, since the color ink is injected after the clear ink has been injected and the characteristics of the printing paper P have been improved, it is possible to prevent bleeding and to improve the coloring, fixing, or drying properties. Become.

  When using clear ink which is preferably discharged after the color ink, first, after the color inks are discharged and the respective hues are superimposed, finally the N ink is discharged from the first nozzle row. You. As a result, since the clear ink is printed after the color ink is sufficiently fixed, the influence of the clear ink on the color ink can be reduced, and good color development can be obtained.

FIG. 1 is a diagram illustrating a schematic configuration of a printer and a printing computer system according to a first embodiment. FIG. 2 is a block diagram showing a configuration of a main part of the printer centering on a control circuit in the printing computer system shown in FIG. 1. FIG. 2 is a block diagram illustrating a detailed configuration of a computer in the printing computer system illustrated in FIG. 1. FIG. 4A is a diagram illustrating an arrangement of nozzles in the print head 12, and FIG. 4B is a diagram illustrating a positional relationship between the nozzle rows R2 to R5 and the printing paper P during printing. FIG. 2 is a diagram illustrating functions of driver software included in the computer illustrated in FIG. 1. FIG. 2 is a diagram illustrating an example of a dot pattern formed on printing paper by the printer illustrated in FIG. 1. FIG. 13 is a diagram illustrating another configuration example of the print head of the printer according to the second embodiment. 8A is a diagram illustrating another configuration example 1 of the print head, and FIG. 8B is a diagram illustrating another configuration example 1 of the print head. FIG. 9A is a sectional view of a dot formed by a dye-based ink, and FIG. 9B is a sectional view of a dot formed by a pigment-based ink. FIG. 14 is a diagram illustrating a schematic configuration of a printer and a printing computer system according to a third embodiment. FIG. 11 is a block diagram illustrating a configuration of a main part of a printer centering on a control circuit in the printing computer system illustrated in FIG. 10. FIG. 11 is a block diagram illustrating a detailed configuration of a computer in the printing computer system illustrated in FIG. 10. FIG. 13A is a diagram illustrating an arrangement of nozzles in the print head 1012, and FIG. 13B is a diagram illustrating a positional relationship between the nozzle rows R2 to R5 and the printing paper P during printing. FIG. 11 illustrates functions of driver software included in the computer illustrated in FIG. 10. FIG. 11 is a diagram illustrating a relationship between a color ink ejection amount per unit area and a clear ink ejection amount in the printer illustrated in FIG. 10. FIG. 11 is a schematic diagram of a cross section of a dot formed on printing paper by the printer shown in FIG. 10. FIG. 11 is a diagram illustrating an example of a dot pattern formed on printing paper by the printer illustrated in FIG. 10. FIG. 14 is a diagram illustrating a configuration example of a print head of a printer according to a fourth embodiment. FIG. 19A is a diagram illustrating another configuration example 1 of the print head, and FIG. 19B is a diagram illustrating another configuration example 2 of the print head.

Explanation of reference numerals

12, 12A, 12B, 1012, 1012A, 1012B Print head 22, 1022 Printer (printing device)
90, 1090 Computer R2 to R4 Nozzle row (second nozzle row)
R5 nozzle row (first nozzle row)
Ra1, Ra6 (first nozzle row)
Ra2 to Ra5 (second nozzle row)

Claims (26)

(A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head having a plurality of nozzles for ejecting ink to form dots on a medium transported by the transport mechanism,
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
A printing device having
The printing apparatus, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the transport direction. The printing device according to claim 1,
In the transport direction, the first nozzle row is disposed upstream of the second nozzle row. 3. The printing device according to claim 2, wherein
The second nozzle row has a plurality of nozzle rows for ejecting inks of different colors. 3. The printing device according to claim 2, wherein
The ink having no coloring material is an ink that is desirably ejected before the ink having the coloring material. The printing device according to claim 4, wherein
The ink having no coloring material is an ink that causes a chemical reaction with the ink having the coloring material. The printing device according to claim 5, wherein
The ink having no coloring material is an ink for the purpose of preventing bleeding, improving coloring properties, improving fixing properties, or improving drying properties. The printing device according to claim 1,
In the transport direction, the first nozzle row is disposed downstream of the second nozzle row. The printing device according to claim 7,
The second nozzle row has a plurality of nozzle rows for ejecting inks of different colors. The printing device according to claim 7,
The ink having no coloring material is an ink that is desirably printed after the ink having the coloring material. The printing device according to claim 9,
The ink having no coloring material is an ink for the purpose of preventing bleeding, improving coloring properties, improving fixing properties, or improving drying properties. The printing device according to claim 1,
In the transport direction, the first nozzle row is disposed upstream and downstream of the second nozzle row, and the first nozzle row appropriately discharges the ink having no color material. I do. (A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head that has a plurality of nozzles for ejecting ink to form dots on a medium conveyed by the conveyance mechanism, and moves in a predetermined direction to perform printing.
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
Has,
The printing apparatus, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the predetermined direction. The printing device according to claim 12, wherein
In the predetermined direction, the first nozzle row is arranged downstream of the second nozzle row. The printing device according to claim 12, wherein
In the predetermined direction, the first nozzle row is disposed upstream of the second nozzle row. The printing device according to claim 12, wherein
In the predetermined direction, the first nozzle row is disposed on the upstream side and the downstream side of the second nozzle row, and the first nozzle row appropriately discharges the ink having no color material. I do. (A) a transport mechanism for transporting the medium in the transport direction;
(B) A print head which has a plurality of nozzles for ejecting ink to form dots on a medium conveyed by the conveyance mechanism, and performs printing by moving in a predetermined direction and a reverse direction. ,
A first nozzle row having a plurality of nozzles arranged in the transport direction for discharging ink having no color material,
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
A print head with
Has,
In the predetermined direction, the first nozzle row is disposed upstream and downstream of the second nozzle row, respectively.
A printing apparatus which performs printing using one of the first nozzle rows arranged on the upstream side and the downstream side and the second nozzle row during printing. The printing device according to claim 16,
At the time of printing, among the first nozzle rows arranged on the upstream side and the downstream side, the first nozzle row located on the leading side in the direction in which the print head moves, and the second nozzle row Printing is performed using the nozzle array. The printing device according to claim 16,
At the time of printing, of the first nozzle rows arranged on the upstream side and the downstream side, the first nozzle row located on the rear side in the direction in which the print head moves, and the second nozzle row Printing is performed using the nozzle array. A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
The print head, wherein the first nozzle row is arranged on at least one of an upstream side and a downstream side of the second nozzle row in the transport direction. 20. The print head according to claim 19, wherein:
The first nozzle row is arranged upstream of the second nozzle row in the transport direction. 20. The print head according to claim 19, wherein:
The first nozzle row is arranged downstream of the second nozzle row in the transport direction. 20. The print head according to claim 19, wherein:
The first nozzle row is disposed upstream of the second nozzle row in the transport direction, and is disposed downstream of the second nozzle row in the transport direction. The ink having no coloring material is appropriately ejected from the nozzle row. A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
In the transport direction, the first nozzle row is disposed on at least one of an upstream side and a downstream side of the second nozzle row,
A print head in which the ink having no color material is ejected from the first nozzle row before the ink is ejected from the second nozzle row. A print head having a plurality of nozzles for ejecting ink to form dots on a medium,
A first nozzle row having a plurality of nozzles for ejecting ink having no color material, the plurality of nozzles being arranged in the transport direction of the medium;
A second nozzle row including a plurality of nozzles for ejecting ink having a color material, the nozzle rows being arranged in the transport direction,
Has,
In the transport direction, the first nozzle row is disposed on at least one of an upstream side and a downstream side of the second nozzle row,
A print head in which the ink having no color material is ejected from the first nozzle row after the ink is ejected from the second nozzle row. A printing method,
Transporting the medium in the transport direction;
Discharging ink having no color material onto the medium;
Ejecting the ink having no coloring material onto the medium, and then ejecting the ink having the coloring material;
A printing method. A printing method,
Transporting the medium in the transport direction;
Discharging ink having a color material onto a medium;
Ejecting the ink having the coloring material onto the medium, and then ejecting the ink having no coloring material;
Printing method having

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